Recording medium for storing write protection information and write protection method thereof

ABSTRACT

A recording medium storing a write protection information, and a write protection method for protecting data recorded on a recordable and/or rewritable disc from unwanted overwriting or erasing. In order for write protection of a disc in a bare state that is usually used in a cartridge having a recognition switch for write-protection, such as a DVD-RAM, write protection information is recorded in a Lead-in area, a Lead-out area or a recording information area other than a user data area of the disc, and the data is protected from unwanted overwriting or erasing using the write protection information. Also, even though the write protection information stored on a disc does not match the state of a recognition switch of a case for write-protection, the data can be prevented from unwanted overwriting or erasing. Thus, the write protection can be ensured when a recordable and/or rewritable recording medium, such as DVD-RAM, DVD-R and DVD-RW, is used in a bare state.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of application Ser. No.10/779,767, filed Feb. 18, 2004, now pending, which is a ContinuationApplication of application Ser. No. 10/107,147 filed Mar. 28, 2002, nowU.S. Pat. No. 6,741,535, which is a Divisional Application ofapplication Ser. No. 09/610,695, filed Jul. 5, 2000, now U.S. Pat. No.6,744,713, which is a Divisional Application of Parent application Ser.No. 09/333,520, filed Jun. 15, 1999, now U.S. Pat. No. 6,724,705, andclaims the benefit of Korean Application Nos. 98-22390, filed Jun. 15,1998; 98-23917, filed Jun. 24, 1998; 98-39727, filed Sep. 24, 1998;98-54190, filed Dec. 10, 1998; and 99-4679, filed Feb. 10, 1999, in theKorean Patent Office, the disclosures of which are incorporated in thepresent application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to optical recording and/or reproductionfor recording digital data on a disc and/or reproducing the datatherefrom, and more particularly, to a write protection method forprotecting data recorded by a user on a write-once or rewritable mediumfrom unwanted overwriting or erasing, and a recording medium for storingthe write protection information.

2. Description of the Related Art

A DVD-R (Digital Versatile Disc-Recordable) standard and a WORM (WriteOnce Read Many) standard are standards for a write-once disc, and aDVD-RAM (Digital Versatile Disc Random Access Memory) standard and aDVD-RW (Digital Versatile Disc-Rewritable) standard are standards for arewritable disc.

According to the DVD-RAM standards published in July of 1997, DVDSpecifications for Rewritable Disc, Part 1 Physical SpecificationsVersion 1.0, a DVD-RAM adopts a cartridge containing a disc, and discsfrom Type 2 and Type 3 cartridges can be used, after removal from thecartridge, as bare discs.

Three types of cartridges for a DVD-RAM are defined as follows. In theType 1 cartridge, a single sided disc or double sided disc is installedin the cartridge and the installed disc can not be taken out of thecase. In the Type 2 cartridge, a single sided disc is installed and theinstalled disc can be taken out of the case. However, when the disc istaken out of the case once, a sensor hole capable of sensing the removalof the disc is permanently changed into an open state, so that thesensor hole cannot be changed into a closed state again. Thus, it can bedetermined whether or not the disc has been taken out of the case. Also,in the Type 3 cartridge, a sensor hole capable of determining whether ornot a disc has been taken out of the case is open in response to thedisc being taken out of the case, so the disc can be taken out of or putinto the case without restrictions.

Also, in each of Types 1 through 3, the cartridge has a write-inhibithole (alternatively called “recognition switch for write protection”)and according to the standard at page PH-69, writing is possible whenthe write-inhibit hole is closed and is impossible when thewrite-inhibit hole is open. That is, when a user intends to protect datawritten by the user from unwanted overwriting or erasing, thecorresponding write-inhibit hole in a closed state is changed into anopen state, such that a recording apparatus cannot record to the disc ofthe corresponding cartridge.

However, in the instance of using the Type 2 or Type 3 cartridge, a baredisc can be used without the case as described above. This is so thedisc can be used in a thin recording/reproducing apparatus such as alaptop computer which cannot adopt a cartridge. However, the abovespecifications do not define any write-protect means other than thewrite-inhibit hole attached to the case of the cartridge.

For example, when a user, after removing a disc installed in a case thatprotects from writing, inserts the disc into to a thinrecording/reproducing apparatus that cannot accept a cartridge, thewrite protection by the write-inhibit hole is no longer effective.

Also, there are many DVD related specifications such as a DVD-ROMspecification (DVD specification for Read Only Memory), and a DVD-Rspecification (DVD specification for Recordable Disc). Also, manyspecifications for rewritable DVD, which are not established yet, can beconsidered, e.g., a DVD specification for a rewritable and readabledisc, which is very similar to the DVD-R specification, and a DVDspecification for a disc with enhanced density. Such a series ofspecifications with the prefix of DVD are called the “DVD family.”

Also, a computer operating system adopts various attributes, e.g.,read-only and write protection, which is capable of preventing anarbitrary change in written data using attributes of a file that storesthe data. However, when a disc is managed at a level lower than that ofa file system for managing the file, for example, when the recording andreproduction are directly performed, not via the file system, when thedisc is initialized, where the entire file system may not be referred,or in the case that attributes of each file cannot be considered, such amethod is not a perfect protection method. A method of protecting dataof a bare DVD-RAM from unwanted overwriting or erasing has not yet beenintroduced.

In the case of a DVD-RAM, a disc can be used in a bare state as well aswith the case on. However, in the instance of a DVD-R or a DVD-RW, adisc in a case cannot be used, so that the need to protect the bare discfrom unwanted overwriting or erasing has increased. However, when a baredisc taken out of a case is used, it is not possible to utilize thewrite-inhibit hole, so the write protection must be provided on the discitself.

In the DVD-R specification, a 3.95 GB specification (Version 1.0) and a4.7 GB specification (final draft, Version 1.9) do not mention a writeprotection method for a bare disc. Meanwhile, DVD-RW specifications arebeing prepared based on the DVD-R specification, and particularly,Version 1.9 defines the use of a bare disc without a case. However, if afuture specification defines the use of a disc in a case (for example,extension of application), there will be no write protection method tobe applied to a bare disc since the conventional write protectionmethod, which has been applied to a DVD-RAM using the write-inhibithole, is used.

Further, if the DVD-RW specification allows the use of a case, writingcan be prevented using a write-inhibit hole as in the DVD-RAM. However,if a user forgets to change the write-inhibit hole into a write-inhibitposition, unwanted erasing or overwriting of data can occur.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a recording mediumin which write protection information is stored on a disc contained in acase.

It is another object of the present invention to provide a recordingmedium in which write protection information capable of protecting abare disc from unwanted overwriting or erasing is stored on the disc,when the bare disc has been taken out of a case.

It is still another object of the present invention to provide a writeprotection method for a recording and/or reproducing apparatus, capableof protecting information written on a recordable and/or rewritablemedium from being undesirably overwritten or erased.

To achieve the first and second objects of the present invention, thereis provided a recordable and/or rewritable recording medium which may becontained in a case of a cartridge or may be in a bare state, whereinthe recording medium stores write protection information capable ofprotecting the data recorded on the recording medium from unwantedoverwriting or erasing.

To achieve the third object of the present invention, there is provideda write protection method for an optical disc recording and/orreproducing apparatus, wherein data recorded on a recordable orreproducible recording medium including a Lead-in area, a Lead-out areaand a user data area is protected from unwanted overwriting or erasing,the method comprising the steps of: (a) checking write-protectioninformation stored on the recording medium; and (b) prohibiting writingof data on the recording medium according to the write protectioninformation.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and advantages of the present invention will becomemore apparent by describing in detail preferred embodiments thereof withreference to the attached drawings in which:

FIG. 1 is a perspective view of a cartridge for a DVD-RAM (DigitalVersatile Disc Random Access Memory), having a write-inhibit hole;

FIG. 2 shows the structure of a general DVD-RAM;

FIGS. 3A and 3B show the data structure of a defect management area(DMA) of a general DVD-RAM;

FIGS. 4A and 4B show examples of the data structure of the DMA of aDVD-RAM, for storing write protection information, according to anaspect of the present invention;

FIGS. 5A and 5B show further examples of the data structure of the DMAof a DVD-RAM, for storing write protection information, according to anaspect of the present invention;

FIGS. 6A and 6B are flowcharts illustrating a write protection methodaccording to a first embodiment of the present invention;

FIG. 7 is a flowchart illustrating a method of updating write protectioninformation according to the present invention;

FIG. 8 shows the structure of a disc identification zone for storing thewrite protection information according to the present invention;

FIG. 9 shows the data structure of the write protection informationstored in the disc identification zone of FIG. 8;

FIG. 10 shows the structure of a disc satisfying general DVD-R andDVD-RW specifications;

FIG. 11 shows the structure of a Lead-in area shown in FIG. 10;

FIG. 12 shows the structure of a control data zone shown in FIG. 11;

FIG. 13 shows the contents of an RMD (Recording Management data) fieldof an RMA (Recording Management Area) according to the DVD-R and DVD-RWspecifications;

FIG. 14 shows the contents of the conventional RMD field 0 shown in FIG.13;

FIG. 15 shows the contents of the RMD field 0 for storing the writeprotection information according to the present invention; and

FIG. 16 is a flowchart illustrating a write protection method accordingto a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, where the write-inhibit hole of a cartridgeaccording to the DVD-RAM specification is shown, reference numeral 1represents a write-inhibit hole and a reference numeral 2 represents asensor hole used to determine whether a disc has been taken out of acase. According to the DVD specifications for rewritable Disc/Part IPhysical Specifications Version 1.9, the sensor holes A1, A2 and A3should be on side B of the case, and corresponding sensor holes B1, B2and B3 should be on side A of the case. When A1 is closed, the disk hasnever been removed from the case. When A1 is open, the disk has beenremoved from the case at least once. When A2 is closed, it representsthe active side, and when A2 is open, it represents the non-active side.A3 is reserved.

In FIG. 1, a closed write-inhibit hole 1 indicates that writing isallowed, and an open write-inhibit hole 1 indicates that writing isprohibited. Thus, when the write-inhibit hole 1 is opened, in thecorresponding DVD-RAM recording/reproducing apparatus, writing of datato a disc is prohibited even if a write command is input from theoutside, so that information written on the disc can be protected fromunwanted overwriting.

FIG. 2 shows the structure of a disc according to the DVD-RAMspecification. The disc comprises three parts, i.e., a Lead-in area, auser data area and a Lead-out area, according to the aspect of function.Also, the disc can be classified into a rewritable area, an unwritablearea and a mirror area distinct from the rewritable area and theunwritable area. In particular, the Lead-in area contains a read-onlyzone in the innermost part, which is an unwritable embossed data zonehaving pits, and a rewritable data zone following the read only zone, inwhich both recording and playback are possible. Meanwhile, the Lead-outarea and the user data area are only formed of the rewritable data zone.The read-only zone of the Lead-in area contains information aboutphysical specifications of the disc. The rewritable data zone of each ofthe Lead-in area and the Lead-out area contain two defect managementareas DMA 1, DMA 2 or DMA 3 and DMA 4 in which information about discdefects is written, a disc test zone for use by a disc manufacturer inchecking the status of the disc, a drive test zone for testing recordingand reproduction operations in a recording/reproducing apparatus, aguard track zone for connecting each zone, and a disc identificationzone.

In the DVD-RAM specification version 1.0, the purpose for the discidentification zone and the content thereof are not yet clearlydescribed.

FIGS. 3A and 3B show the data structure in each defect management area(DMA) described at pages PH-155 through PH-158 of the DVD-RAMspecification, and in particular, they show the data structure of a disccertification flag and a group certification flag respectively, in adisc definition structure (DDS) area of the DMA.

A total of four defect management areas DMA 1, DMA 2, DMA 3 and DMA 4are present in the Lead-in area and the Lead-out area of a disc, whereinDMA 1 and DMA 2 exist in the Lead-in area and DMA 3 and DMA 4 exist inthe Lead-out area, and identical information relating to disc defectsand initialization of the disc is stored in each area. Writing suchidentical information in different areas, i.e., in two areas DMA 1 andDMA 2 of the Lead-in area and in two areas DMA 3 and DMA 4 in theLead-out area, is done to prevent the problem of data becoming unusabledue to disc defects.

In the byte position 3, i.e., BP3, of the disc definition structure(DDS), a disc certification flag as shown in FIG. 3A is present, and thedisc certification flag comprises “In Process” information indicatingthe initialization state of the disc, a “User certification” flagindicating whether the disc is certified by a user, and a “Discmanufacturer certification” flag indicating whether the correspondingdisc is certified by a disc manufacturer, and flag information writtenin the byte position BP3 is information about the entire disc.

Also, in the byte positions 16 to 39, BP1{tilde over (6)}BP39, each bytehas a group certification flag as shown in FIG. 3B in an identicalconfiguration. The byte positions BP1{tilde over (6)}BP39 haveinitialization information about 24 recordable areas, i.e., a group,defined in the DVD-RAM specification version 1.0. That is, each groupcertification flag has “In Process” information indicating theinitialization state of the corresponding group and a “Usercertification” flag indicating whether the disc is certified by a user.Here, the group refers to specific recordable areas of the disc.

FIGS. 4A and 4B are examples of the data structures of a disccertification flag and a group certification flag of the disc definitionstructure (DDS) area of the defect management area (DMA) that storeswrite protection information according to the present invention. In thedata structure of the disc certification flag shown in FIG. 4A, “Discwrite protection” information is stored in bits b4 and b3 of a reserveddisc certification flag “Reserved”, in contrast to the data structure ofthe disc certification flag shown in FIG. 3A, and is defined as follows.

Disc Write Protection

-   -   b4, b3=00b: Disc is not write protected        -   10b: Disc is write protected Entire disc shall not be            written to except for drive test zone, and DMA area        -   11b: Disc is write protected Entire disc shall not be            written to These bits shall not be modified to other values    -   Others: Reserved

In the same manner, the data structure of the group certification flagshown in FIG. 4B stores “Group write protection” information in bits b4and b3 of a reserved group certification flag “Reserved”, in contrast tothe data structure of the group certification flag shown in FIG. 3B, andis defined as follows.

Group Write Protection

-   -   b4, b3=00b: Group is not write protected        -   10b: Group is write protected. User data shall not be            written to this block    -   Others: Reserved

The states of the bits b4 and b3 of the disc certification flag, andthose of the bit b4 and b3 of the group certification flag are shown inTable 1.

TABLE 1 disc group certifi- certifi- cation cation flag flag b4 b3 b4 b3states 0 0 0 0 No write protection 0 0 1 0 Given group is writeprotected 1 0 Don = t Soft write protected on entire disc 1 1 care Hardwrite protected on entire disc

In the above Table 1, soft write protection means that write protectioncan be released, that is, that the write protection state can be changedto a rewritable state by setting the corresponding bit b4 to A0″. Also,hard write protection means that write protection is applied to theLead-out area as well as to the Lead-in area, so that the writeprotection state can not be restored to the rewritable state.

In the hard write protection for the group, making a part of the dischard write-protected does not provide advantages to a user in use,rather than in a technical aspect, and particularly, there is a problemof processing in the corresponding group when the entire disc isreinitialized. Thus, it is unfavorable to set the hard write protectionfor the group.

As shown in the data structure of FIGS. 4A and 4B, the write protectioninformation of the disc is written in the disc definition structure(DDS) of the defect management area (DMA), and identical writeprotection information is written four times to the same disc, so thatrobustness of the write protection information on the disc is enhanced.

When a bare disc that is write protected is inserted for use into acase, the write-inhibit hole of which is in a rewritable state, or if abare disc that is not write protected is inserted into a case, thewrite-inhibit hole of which is in a write protection state, the writeinhibition information stored on the disc cannot match the state of thewrite-inhibit hole of the case.

In such a case, if either one of the disc or the case is writeprotected, it is preferable to operate to be suitable for the writeprotection state. This is because in the user=s position it ispreferable that the content of data be checked again without overwritingrather than important data being damaged or erased through overwriting.

FIGS. 5A and 5B are further examples of the data structures of the disccertification flag and the group certification flag, respectively, ofthe disc definition structure (DDS) area of the defect management area(DMA) that stores the write protection information according to thepresent invention.

In the case where the write protection information is in the disccertification flag shown in FIG. 5A, it is possible that only one bit b4be used regardless of whether the write protection information is forthe hard write protection or for the soft write protection, which isdefined as follows.

Disc Write Protection

-   -   b4=0b: Disc is not write protected        -   1b: Disc is write protected Entire disc shall not be written            to except for drive test zone, and DMA area

The group test flag shown in FIG. 5B can store the write protectioninformation using only one bit b4, which is defined as follows.

Group Write Protection

-   -   b4=0b: Group is not write protected        -   1b: Group is write protected User data shall not be written            to this block

In this case, preferably bit b4 of the disc certification flag and thebit b4 of the group certification flag are used. However, instead ofusing the bit b4 of the disc certification flag or group certificationflag, any “Reserved” bits can be used.

Also, the bit b4 of the group certification flag, that is, “Group writeprotection” flag, may not be used. This is effective in a disc in whichonly a specific group is not write protected, and in this case the bitb4 of the group certification flag is “Reserved” as in the conventionalspecifications, like as shown in FIG. 3B.

The present invention can be applied to a case without a write-inhibithole, and information on the disc can be efficiently protected in thiscase using the write protection information stored on the disc.

FIGS. 6A and 6B are flowcharts illustrating a write-protection methodaccording to a first embodiment of the present invention. First, it ischecked whether a disc is installed in a case (step S101), and if thedisc is installed in the case, the state of the write-inhibit hole ofthe case is checked (step S102). That is, when the write-inhibit hole isclosed, it means that cartridge is not write protected. When thewrite-inhibit hole is open, it means that the cartridge is writeprotected.

If it is determined in step S101 that the disc is not installed in thecase, or after the state of the write-inhibit hole is checked in stepS102, a write protection flag of the disc is checked (step S103). Thatis, write protection flags within the disc certification flag and thegroup certification flag of the DDS in each DMA are checked.

It is determined whether the write protection information of the discmatches the state of the write-inhibit hole of the case (step S104).That is, when write protection information is written on the disc andthe write-inhibit hole of the case is open, it is determined whether thewrite protection flag of the disc certification flag is set to a “writeprotection” state (step S105). Otherwise, a user is informed of that thewrite protection information of the disc does not match the state of thewrite-inhibit hole of the case (step S106).

If the write protection flag of the disc certification flag is set as awrite protection state in the step S105, or if one of either the disc orthe case indicates the write protection state even though both thewrite-protection states of the disc and the case do not match in thestep S106, it is checked whether the disc is set to a “hard writeprotection” state (step S107). If the disc is set to the “hard writeprotection” state, data writing to the entire disc including the Lead-inarea and the Lead-out area in addition to the user data area isprohibited (step S108). Otherwise, data writing in the user data area,and except for the drive test zone and the defect management area (DMA),is prohibited (step S109).

If it is determined in the step S105 that the write protection flag ofthe disc certification flag is not set to the “writing protection”state, it is checked whether the write protection flag of the groupcertification flag is set to the “write protection” state (step S110).If the write protection flag of the group certification flag is set to a“write protection” state, writing data in the corresponding group isprohibited (step S111). Otherwise, data writing is allowed in therewritable area (step S112).

The write protection method illustrated in FIGS. 6A and 6B correspondsto the case of using the disc certification flag containing the hardwrite protection flag shown in FIG. 4A, and the group certification flagshown in FIG. 4B. When the disc certification flag of FIG. 5A and thegroup certification flag of FIG. 5B are used, the steps S107 and S108illustrated with reference to FIGS. 6A are not performed. When the disccertification flag is set to the “write protection” state in the stepS105, writing data in the user data area is prohibited in step S109.

FIG. 7 is a flowchart illustrating a method of setting a rewritable discto the write protection state or of changing the write protection stateof the disc to a rewritable state. A method of updating the writeprotection information will now be described with reference to theflowchart of FIG. 7.

In FIG. 7, when a disc or a cartridge is inserted into arecording/reproducing apparatus, the write protection information ischecked (step S201). Then, it is determined whether the write protectioninformation has been input by a user (step S202) and when the writeprotection information is input by the user, it is determined whetherinformation set by the user is for write protection (step S203). If theinformation set by the user is write protection information, thecorresponding write protection flag of the disc is set to the writeprotection state (step S204).

When the information set by the user is not write protection informationin step S203, it is determined whether the information set by the useris write protection release information (step S205). If the informationset by the user is the write protection release information, it isdetermined whether the current disc is in a hard write protection state(step S206). If the current disc is in the hard write protection state,the user is informed that write protection cannot be released (stepS207). If it is determined in step S206 that the disc is not in the hardwrite protection state, the corresponding write protection flag of thedisc is set to the rewritable state (step S208).

Also, when the setting of the write protection or the release of thewrite protection of the disc is completed, that is, the step S204, S207or S208 is completed, and the disc is installed in a case, it isdetermined in step S209 whether the state of the write-inhibit hole ofthe case matches the write protection information stored in the disc. Ifthe state of the write-inhibit hole of the case does not match the stateof the disc, the user is informed of such difference (step S210), andthen the procedure is completed.

The method of updating the write-protection information, illustrated inFIG. 7, can be performed when a bare disc is inserted or a disc in acase is inserted, and can be performed after the write-protection iscontrolled using the write protection information as illustrated withreference to FIGS. 6A and 6B.

In the preferred embodiment of the present invention, the writeprotection information of the disc is written in the defect managementarea of the disc. However, the disc identification zone of FIG. 2 can beused instead of the defect management area of the disc. The discidentification zone is present both in the Lead-in area and the Lead-outarea, like the defect management area of the disc. Thus, writingidentical information two or more times to the disc identification zoneslocated in the Lead-in area and the Lead-out area can ensure robustnessas strong as in the defect management areas of the disc.

Since the disc identification zone is not presently used for a specificpurpose, there is an advantage that the disc identification zone doesnot conflict with the information written in the defect management areaof the disc. In particular, information of the defect information arearelates to only the DVD-RAM, it is difficult to maintain consistencybetween discs for optical recording/reproduction. Meanwhile, since thedisc identification zone is not restricted to a specific disc, the discidentification zone can maintain consistency with another discsatisfying the similar specifications.

An example of storing the write protection information using the discidentification zone will be described with reference to FIGS. 8 and 9.

As shown in FIG. 8, in the structure of a disc identification zone thatstores write protection information for a bare disc, four flags forwrite protection are concurrently written to the disc identificationzone, and two or more normal flags of the four flags are read. If thecontents of the read flags matches each other, it is regarded that thewrite protection is set for the disc.

For example, the four flags are written in only the disc identificationzone of the Lead-in area, and disc identification information of 1 blocklength (=1 byte) is successively written four times in the four blocksfrom the start of the disc identification zone of the Lead-in area, andall the first bytes of disc identification information contain a writeprotection flag. The disc identification information of 1 block lengthis summarized as shown in Table 2.

TABLE 2 BP Contents Number of bytes 0 Write protection information 1byte 1 to 32767 Reserved 32767 bytes

The write protection flag of the disc identification informationcorresponds to the most significant bit (MSB) of the first byte as shownin FIG. 9. When the flag (indicated by “WP”) value is 1b (binary), itmeans that the entire area of the disc is write protected except for thedisc identification zone and the drive test zone. Also, when the flagvalue is 0b, it means that the entire area of disc is rewritable. Thatis, “WP” of FIG. 9 is defined as follows.

$\begin{matrix}{{WP} = {1b\text{:}\mspace{14mu}{Entire}\mspace{14mu}{area}\mspace{14mu}{of}\mspace{14mu}{disc}\mspace{14mu}{is}\mspace{14mu}{write}\mspace{14mu}{protected}\mspace{14mu}{except}\mspace{14mu}{for}}} \\{{Drive}\mspace{14mu}{test}\mspace{14mu}{zone}\mspace{14mu}{and}\mspace{14mu}{Disc}\mspace{14mu}{identification}\mspace{14mu}{{zone}.}} \\{= {0b\text{:}\mspace{14mu}{Entire}\mspace{14mu}{area}\mspace{14mu}{of}\mspace{14mu}{disc}\mspace{14mu}{is}\mspace{14mu}{not}\mspace{14mu}{write}\mspace{14mu}{inhibited}}}\end{matrix}$

The reason why only two normal flags are read from the four writtenwrite protection flags is as follows. In the case where only one writeprotection flag is written, an error can be generated in the area inwhich the corresponding flag is written, so that the area cannot beused. Also, in the case where only reading and not writing is allowed,there is a possibility of abnormal operation such that no informationcan be written to the disc permanently by erroneously reading thecorresponding flag.

Meanwhile, when writing write protection information in a plurality oflocations, there is a problem in that the time required for reading thecorresponding information gets longer. That is, the time required for aseries of processes from the insertion of a disc, including readingvarious information from the disc and recognizing the informationrequired for the control of the disc by a microcontroller, can be becomelonger.

However, in the case of updating the write protection information, anoperation only for the updating is performed. That is, becauseinformation is not read, the writing time in units of several hundredsmilliseconds is barely worth consideration. Thus, writing is performedin four locations in consideration of the robustness of information, anderror correction capability is taken into account during the recording.That is, if two errors are not generated, or normally corrected flagsare read and two of them match each other, the write protection state ofthe disc is set without reading the remaining flags, thereby increasingthe operating speed.

The write protection method suggested above is not limited to only theDVD-RAM, and can be applied to a disc that has specifications physicallythe same as DVD-R/RW and similar to the DVD specifications, which willnow be described.

FIG. 10 shows the structure of a disc according to general DVD-R andDVD-RW specifications. The disc is roughly divided into two parts withrespect to functionality, including an R (Recording)-information areaand an information area. The R-information area is divided into a PCA(Power Calibration Area) for calibrating power, and an RMA (RecordingManagement Area) including general information relating to recording,i.e., information about the recording mode of a disc, recording state,optimal power control and border zone, and the information area isdivided into a Lead-in area, data recordable area in which data isrecordable by a user and a Lead-out area that is not defined yet in theDVD-R and DVD-RW specifications.

Here, as shown in FIG. 11, the Lead-in area comprises an Initial zone(contents: 00h) for which a specific purpose is not defined, a referencecode zone (channel bit pattern: 3T-6T-7T) used to control an equalizerfor a radio frequency signal in a drive, first and second buffer zones(contents: 00h) and a control data zone containing the contents shown inFIG. 12.

In FIG. 12, physical format information of the control data zone isabout types and versions of the specifications, disc size, maximumtransmission rate, disc structure (single/dual), recording density anddata region allocation, and the disc manufacturing information isunrelated to compatibility.

FIG. 13 shows the content of an RMD (Recording Management Data) field ofthe RMA according to the DVD-R and DVD-RW specifications. The RMAcomprises an RMA Lead-in area including a system reserved field(contents: 00h) and a unique ID field, and RMD fields. As shown in FIG.13, one RMD block consists of 16 sectors (15 RMD fields), in which thefirst sector is allocated as a linking-loss area, general information ofthe disc is stored in RMD field 0, Optimum Power Control (OPC) relatedinformation is stored in RMD field 1, user specific data (contents: 00h)is stored in RMD field 2, and border zone information is stored in RMDfield 3. Also, in the case of a DVD-R disc according to thespecifications of version 1.9, Rzone (Recording Zone) informationincluding recording items is stored in RMD field 4 through RMD field 12whenever the recording is performed, and RMD field 13 and RMD field 14are reserved. Five identical copies of the RMD block are made.

In the case of a rewritable and erasable DVD-RW disc the specificationsof which are not yet defined, Rzone information is stored in RMD field4, and RMD field 5 through RMD field 12 are allocated to store defectmanagement & certification related information taking reliability,certification before the disc is used and management of defect in useinto consideration. Also, RMD field 13 and RMD field 14 are reserved.

FIG. 14 shows the contents of the general information of a disc storedin the RMD field 0 of FIG. 13. In FIG. 14, byte positions BP0 and BP1store information about RMD format (recorded only with 0001h), byteposition BP2 stores information about the disc status, and byte positionBP3 is reserved. The byte positions BP4 through BP21 store unique discidentifier information that stores the recording date and time of thedata as ASCII code. Pre-pit information is copied over the bytepositions BP22 through BP85, and the remaining byte positions BP86through BP2047 are reserved. Here, in the DVD-R disc, the disc statusinformation stored in the byte position BP2 is defined as follows.

-   -   (BP2) Disc status    -   00b: Indicates that disc is empty    -   01b: Indicates that disc is in Disc-at-once recording mode    -   02b: Indicates that disc is in incremental recording mode    -   03b: Indicates that disc is finalized where incremental        recording is used    -   Others: Reserved

FIG. 15 is an example of a table showing the state where the writeprotection information is stored on the disc adopting the DVD-R andDVD-RW specifications according to the present invention using thegeneral information of a disc stored in RMD field 0 of FIG. 13.

That is, by defining the following using the reserved byte position BP3of RMD field 0, information that the current disc is write protected canbe transmitted to a drive.

-   -   (BP3) Disc write protection flag    -   00b: Indicates that disc is not write protected    -   01b: Indicates that disc is write protected (hard)    -   02b: Indicates that disc is write protected (soft)    -   Entire disc shall not be written to except for PCA, etc.

In the write protection information according to the present invention,00b indicates that the disc is not write protected, 01b indicates thatthe entire disc is write protected (hard write protection), and 02bindicates that the entire disc except for a part of the disc (e.g., thePCA) is write protected (soft write protection). In the presentembodiment, the write-protection information indicates that the entiredisc is write protected or is not write protected. However, the RMDfield of FIG. 13 is written connected to the previous data whenever newdata is written, so that the write-protection can be set for only thewritten data corresponding to the RMD.

For example, even though write protection information is stored in thebyte position BP3 of RMD field 0, the write protection information on abare disc can be written using the Lead-in area and the Lead-out areashown in FIG. 10 in addition to the RMD area. Also, the byte positionBP2 of RMD field 0 stores the disc status information, so that writeprotection information can be stored in the byte position BP2 of RMDfield 0.

Since the write protection information cannot be updated in theonce-writable DVD-R, in consideration of the consistency with the DVDfamily, write protection information can be indicated throughfinalization that means the writing on the defined Lead-in area andLead-out area. “Finalization” means the completion of writing in theLead-in area and the Lead-out area as well as in the user data area, ofa once-writable DVD-R disc. That is, that the finalization has beenperformed (completed) indicates the DVD-R is write-protected. Otherwise,it means that there is no write protection.

Also, as in the defect management area DMA 1, DMA 2, DMA 3 and DMA 4 ofthe DVD-RAM, the same content is recorded multiple times to cope witherrors, thereby ensuring robustness. In the DVD-R/RW, such robustness isensured by grouping RMDs of the RMA and providing the RMDs belonging toone group with the same content.

A disc must include format information informing whether the currentdisc is a DVD-R or a DVD-RW, such that a DVD-R disc and a DVD-RW disc iscompatible in the same drive. As shown in FIG. 15, the RMD format can bedefined using the byte positions BP0 and BP1 of RMD field 0 as follows.

-   -   (BP 0,1) RMD format    -   0001h for R    -   0002h for RW    -   0003h for R/RW compatible mode

FIG. 16 is a flowchart illustrating a write protection method accordingto a second embodiment of the present invention, in consideration ofapplication extension to a DVD-RW contained in a case.

First, it is determined whether a disc is installed in a case (stepS301). If the disc is installed in the case, the state of awrite-inhibit hole of the case is checked (step 302). That is, if thewrite-inhibit hole is closed, it means that cartridge is not writeprotected, and if the write-inhibit hole is open, it means that thecartridge is write protected.

When the disc is not installed in the case in step S301, or when thestate of the write-inhibit hole is checked in step S302, thewrite-protection flag of the disc is checked (step S303). That is, awrite protection flag within RMD field 0 is checked.

Then, it is determined whether the write protection information of thedisc matches the state of the write-inhibit hole of the case (stepS304). That is, when the write protection information is written on thedisc and the write-inhibit hole of the case is opened, it is determinedthat the write protection flag is in a “write protection” state (stepS305). Otherwise, the user is informed that the write protectioninformation of the disc does not match the state of the write-inhibithole of the case (step S306).

If the write protection flag of the disc is set to the “writeprotection” state in step S305, or after the step 306, that is, ifeither the disc or the case is in a “write protection” state even thoughthe write protection information of the disc does not match the state ofthe write-inhibit hole of the case, it is determined whether the disc isset to the “hard write protection” state (step S307). If the disc is inthe “hard write protection” state, the entire disc including the userdata area is write-prohibited (step S308). Otherwise, only the user dataarea is write protected (step S309). Also, in the step S305 if the writeprotection flag is not in the “write protection” state, the disc is notwrite-protected (step S310).

In a recordable and/or rewritable medium according to the presentinvention, e.g., a disc satisfying the DVD specifications, e.g.,DVD-RAM, DVD-R and DVD-RW, data of a bare disc that is not contained ina case can be efficiently protected. Also, when either the case or thedisc is in the write protection state, the writing of data is prohibitedand the user is allowed to check the state of a disc or a cartridge. Asa result, the data recorded on the disc can be protected efficientlyfrom unwanted overwriting or erasing.

1. A write protection method for an optical disc recording and/orreproducing apparatus, wherein data recorded on a recordable and/orreproducible recording medium including a Lead-in area, a Lead-out areaand an entire user data area, is protected from unwanted overwriting orerasing, the method comprising: checking a state of the recording mediumprovided by a plurality of identical write protection information thatis stored in a disc identification zone in the Lead-in area or Lead-outarea of the recording medium, at the same time, with the discidentification zone structure complying with a DVD specification; andprohibiting writing of data on the recording medium according to thestate of the recording medium, wherein the checking of the state of therecording medium comprises checking whether the plurality of identicalwrite protection information are read without error and have a matchingstate.
 2. The write protection method of claim 1, wherein the pluralityof identical write protection information is redundantly stored, at thesame time, in the disc identification zone of at least one of theLead-in area and the Lead-out area of the recording medium, theplurality of identical write protection information being redundantlystored in physically separate locations of each of the at least one discidentification zone.
 3. A write protection method for an optical discrecording and/or reproducing apparatus which records and/or reproducesdata on/from a recording medium positioned in a case of a cartridge,wherein the recording medium includes an entire user data area to storethe data, and a plurality of identical write protection information thatis stored at the same time, in the recording medium, indicative ofwhether to prevent writing of new data on the recording medium, and thecase has a write inhibit hole for write protection, the methodcomprising: determining a write protection state of the recording mediumprovided by the write protection information and a write protectionstate of the write inhibit hole of the case; and preventing writing ofthe new data on the recording medium if the write protection state ofthe recording medium or the write protection state of the write inhibithole indicates a state to be that of preventing the writing of the newdata on the recording medium.
 4. A write protection method for anoptical disc recording and/or reproducing apparatus, wherein datarecorded on a recordable and/or reproducible recording medium includinga Lead-in area, a Lead-out area, and an entire user data area, isprotected from unwanted overwriting or erasing, the method comprising:checking a write protection state of the recording medium provided by aplurality of identical write protection information that is stored, atthe same time, in the recording medium; and prohibiting writing of dataon the recording medium according to the write protection state of therecording medium, wherein the recording medium stores the writeprotection information to protect the data recorded on the recordingmedium from unwanted overwriting or erasing, with the write protectioninformation being stored redundantly in the Lead-in area of therecording medium, and wherein the checking of the write protection stateof the recording medium comprises checking whether the plurality ofidentical write protection information are read without error and have amatching state.